Garmin G1000 Nxi System Maintenance Manual page 279

2. Press the SPKR key on pilot's audio panel and verify that the selected audio is heard
over the pilot's speaker.
3. On the copilot's audio panel, select the audio source corresponding to each installed
avionics unit (i.e. NAV1, NAV2, COM1, COM2, ADF and DME) and check for audio over
the copilot's headset.
4. Press the SPKR key on copilot's audio panel and verify that the selected audio is heard
over the copilot's speaker.
Failsafe Operation Check – GMA 1347D #1
1. Turn the GMA 1347D #1 off by pulling the AUDIO NO 1 circuit breaker. This directs all
COM 1 phone audio, MIC audio and MIC key to the pilot's position.
2. Check the failsafe operation by exercising the COM 1 boom mic, hand mic, microphone
key and audio over the headphones. All volume control for the COM audio should be
through the PFD volume control. Verify proper operation of COM 1 using the failsafe
operation.
3. Close the AUDIO NO 1 circuit breaker to continue testing.
Failsafe Operation Check – GMA 1347D #2
1. Turn the GMA 1347D #2 off by pulling the AUDIO NO 2 circuit breaker. This directs all
COM 2 phone audio, MIC audio and MIC key to the co-pilot's position.
2. Check the failsafe operation by exercising the COM 2 boom mic, hand mic, microphone
key and audio over the headphones. All volume control for the COM audio should be
through the PFD volume control. Verify proper operation of COM 2 using the failsafe
operation.
3. Close the AUDIO NO 2 circuit breaker to continue testing.
Marker Beacon Test
1. Using a ramp tester, simulate the outer marker, middle marker, and inner marker signals
by following the test equipment manufacturer's instructions. Verify that each marker
audio signal is present over the pilot and co-pilot headphones and speaker.
2. Verify that the outer, middle, and inner annunciations appear on PFD 1 and PFD 2 when
the corresponding signal is applied. Marker beacon annunciations (
appear at the upper left corner of the altitude indicator on the PFD. Operate the MKR
MUTE key on the #1 and #2 GMA 1347D and ensure that the audio signal is muted.
3. If no other service is to be performed, continue to the return-to-service checks in Section
9.
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
, , and )
Page 266
Revision 1